That last bit is crucial - surround yourself with people smarter than you - otherwise you'll spend most of your time solving complex problems in inefficient ways, which could very much work against you.
Yes. A thousands times, yes! Some people find themselves to be the smartest person in the room and think, "I've made it!" Others, in the same situation think, "Time to move on..."
Agree completely. The moment you can't learn from those surrounding you is when you start to stagnate.